Indirectly heated coil for boilers with vertical sections



Oct. 21, 1952 A. J. DONOHUE 2,614,542

INDIRECTLY HEATED COIL FOR BOILERS WITH VERTICAL SECTIONS Filed June 21, 1950 2 SHEETSSHEET 1 INVENTOR. ANTHONY J. DGNOHUE J. DONOHUE 2,614,542

A. INDIRECTLY HEATED COIL FOR BOILERS WITH VERTICAL SECTIONS Oct. 21, 1952 Filed June 21, 1950 2 SHEETS-SHEET 2 INVENTOR.

ANTHONY J. DONOHUE BY ATTORNEY Patented Oct. 21, 1952 UNITEDSTATES rerun? OFFICE.

INDIBECTLY HEATED COIL FOR BOILERS WITH VERTICAL SECTIONS Anthony J. Donohue, Mei-ion, Pa. 7 Application June 21, 1950, Serial No. 169,452

" l Claims.

' This invention relates to coils for tankless water heaters adapted for installation indomestic heating boilers of the sectional type which are utilized to supply heat and domestic hot water.

It has heretofore been proposed to install various types of coil or immersion units in an end section of a cast iron sectional heating boiler with the coil disposed below the water line. Installations of this character have not proven wholly satisfactory because of the lack of, circulation within the section in which the coil is inserted and the lack of satisfactory circulation between that section and the other boiler sections through'the top and bottom push nipple openings.

The installation of an immersion heater wholly within one section of domestic boilers produces an appreciable temperature difference between the boiler section in which the'unit is mounted and the other boiler sections. lower settingsof boiler temperature limit controls in order to prevent steaming in steam boilers or lifting of check valves on forced hot water-installations. The use of such lowered boiler water temperatures necessarily reduce the quantity and temperature of domestic hot water which is available.

As-a result of the difficulties encountered in this service cast iron sectional boilers have not been employed to a normal sizes. v The reduction of size of such sectional boilers has only aggravated the difficulties.

In accordance with thepresent invention, an improved coil is provided, suitable for use in sectional cast iron boilers, whether for steam or hot water heating and even though the boiler is of relatively small size and capacity.

In accordance with the present an improved type of domestic water heating coil is provided which is adapted to be inserted in and through one of the nipple openings of the boiler.

' In accordance with the present invention, also, a domesticwater heating coil is provided, for insertion through one of the nipple openings of a cast iron boiler, the coil being constructed to permit of lowering of the same, after insertion, to a position below the normal water line of the boiler.

In accordance with the present invention, also, an improved domestic water heating 'coil' of the submerged type is providedwhich is particularly suitable for use in sectional cast iron boilers and which is effective for both steam and hot water boilers.

Other objects and advantageous features of the invention will be apparent from the specification and claims.

This necessitates invention, also,

The nature and characteristic features of the I invention will be more readily understood from the following description, taken in connection with the accompanying drawings forming part hereof, in which: e

Figure l is a fragmentary sectional view of the upper portion of a sectional boiler, taken from front to rear, and showing the heating coil in operating position therein;

extent in the smaller Fig. 2 isv a fragmentary front elevational view of a portion of the boiler shown in Fig. 1, and illustrating the attaching of the coil head; and

Fig. 3 is a fragmentary sectional view taken approximately on the line 3-3 of Fig. '1, and showing a modified form of connection between the coil and mounting plate. 1 c

. It should, of course, be understood thatthe description and drawings herein are illustrative merely, and that various modifications and changes may be made in the structure disclosed gvithout departing from the spirit of the inven- Like numerals refer to like parts throughout the several views.

Referring now more particularly to the drawings, the upper ends of a plurality of front and rear end sections of a cast iron sectional, boiler are shown at I!) and I l, between which one or more intermediate sections l2 are adapted to-be interposed to provide the desired heating capacity of the boiler. The sections I ll, ll and i2. are connected at their upper portions in the conventional manner by nipples l3 pressed or' otherwise placed in position in alineg nipple openings I4 at iilzie time ,of assembly of the sections Hi, Hand The end sections i0 and II may be provided with the customary t pped openings l5 and 16 for the connection of pipes (not shown), which may serve for the delivery of hot water or steam for use in the heating systemin the usual man ner.

The end section H], in accordance with the present invention, is provided with an opening l8, alined with the nipple openings M of the other sections and preferablyof the same diameter. A coil mounting plate 19 is provided having a sealing gasket 20 which is. secured in fluid tight engagement with the end face of the section Hi by studs 2| and nuts 22. The coil mounting plate I9 is adapted to support the domestic water-heatmg coil, shown generally at 25 and providefor the connection of hot and cold water pipes, as hereinafter explained.

The domestic water heating coil 25 is preferably made of a plurality of section unit coils, the

unit for each section including an outer coil 26 and an inner coil 21.

Each of the outer coils 26, of each section unit, is preferably formed as a helical coil, with a plurality of turns or convolutions, and either right-handed or left-handed, as desired, and with the maximum diameter of the coil 26 slightly less than the interior diameter of the nipples 13. The number of turns in each section coil 26 is determined by the space available in each boiler section [0, H or [2, between the nipples I 3.

The inner section coil 27 are respectively disposed within the outer section coils 26, with a plurality of turns or convolutions, and preferably of the opposite hand from that of the coils 21. The coils 26 and 21 are preferably formed from copper tubing, with an initial outside diameter of the order of inch, and is preferably flattened to permit of a larger number of convolutions in a particular linear distance without unduly increasing the pressure drop across the coil.

The outer coil 26 and the inner coil 21 in the boiler section ID are provided, with terminal ends 28 and 29. The outer ends 28 and 29 are ofiset with respect to the central longitudinal axis of the coil assembly 25 and also offset with respect to the center of the plate l9. The ends 28 and 29 are respectively connected to connectors 39 and 3|. As shown in Figs. 1 and '2, the connectors 30 and 3| each have externally threaded portions for the engagement of nuts 32, washers or gaskets 33 being interposed between the inner heads of the connectors 36 and 3| and the plate 1'9. Upon tightening of the nuts 32, fluid tight connections through the plate 19 are provided.

The connectors 30 and 3 1 are internally threaded as at 34 for theconnection of the cold water supply and hot water delivery pipes for the domestic hot water.

A modified form of connection is shown in Fig. 3, in which the terminal ends 28 and '29 are welded to the connectors 36 and 3| by welds 28 and 29 and the connectors 30 and 3| are welded to the plate l9, by welds 36 and 3 l The inner ends of the coils 2'6 and 27 in the section 10, both ends of the coils 26 and 21 in the intermediate sections II, and the inner ends of the coils 26 and 21 in the boiler section 12 are provided with horizontally disposed tubular portions 35, with connecting sockets 36, to permit of soldering or otherwise joining the outer coils 26 in series and the inner coils 21 in series.

The inner and outer coils26 and 27 in the boiler section H, or at the rear or inner end of the coil 25, are preferably made integral, the connection being effected at the time of making these coils 26 and 2"! by forming these coils from a single continuous piece of tubing. If desired, the lowermost tubular portion 35 of the coils 26 or 21 may have a supporting block 3'! secured tion within the connectingnipples l3, intermediate the ends of the coil assembly .2 5.

It will be noted that the setsof inner and outer coils 26 and 27 are shown as corresponding in number to the number of sections in the boiler, although a lesser number. could be employed, depending upon the particulardomestic water heating capacity desired.

The coil assembly 25, comprisingthe series of thereto, and adapted to rest in supporting relaconnected coils 26 and 21 secured to the plate I9, is inserted through the opening [8 and the inner end advanced respectively through the connecting nipples l3 until the plate I9 is close to the opening H3. The assembly is then dropped or permitted to drop downwardly with each pair of coils 26 and 27 in one of the boiler sections and with the tubular portions spanning the respective nipples l3. The plate I9 is then clamped in position by the nuts 22. The pairs of coils 26 and 27 are thus disposed in pendant position below the normal water level of the boiler which is indicated by the line 38.

I claim 1. In domestic water heating apparatus for a sectional boiler with axially alined connecting members between the water spaces of the boiler sections, the combination comprising a mounting late, .anindirectly heated water heater connected to said plate for insertion through the connecting members and for axial positioning in offset relation to the axis of the connecting members, said water heater having a plurality of tubular water conducting coils each of a length for. reception in a boilersection below the connecting members, said heater coils having tubular water conducting spacing connecting portions therebetween bridging said connecting members.

2. In domestic water heating apparatus for a sectional boiler with axially alined connecting members between the water spaces of the boiler sections, the combination comprising a. mounting plate, an indirectly heated water heater connected to said plate for insertion through the connecting members and for axial positioning in offset relation to the axis of the connecting members, a plurality of tubular water conductingcoils having longitudinal axes alined and normal to said plate and each coil being of a length for reception in a boiler section below the connecting members, said coils having tubular water conducting spacing connecting portions therebetween bridging said connecting members.

3. Apparatus as defined in claim 1 in which the conducting coils have inner and outer coil sections.

4. Apparatus as defined in claim 1 in which the conducting coils have inner and outer coil sections axially oppositely pitched.

ANTHONY J. DONOI-IUE.

REFERENCES CITED The -following references are of record in the file of this patent:

UNITED STATES PATENTS Number Switzerland July 16, 1945 

